-- Discussion containing changed information from previous version are highlighted. --
000
FXUS61 KOKX 211718
AFDOKX

AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE NEW YORK NY
118 PM EDT TUE MAY 21 2013

.SYNOPSIS...
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A FRONTAL BOUNDARY REMAINS JUST NORTH OF THE AREA THIS AFTERNOON THROUGH
WEDNESDAY. A COLD FRONT WILL PASS THROUGH THE AREA THURSDAY
EVENING INTO EARLY FRIDAY. HIGH PRESSURE WILL RETURN FOR THE
WEEKEND AND EARLY NEXT WEEK.
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&&

.NEAR TERM /UNTIL 6 PM THIS EVENING/...
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ADVECTION FOG/STRATUS REMAINS ALONG THE SOUTH SHORE OF SUFFOLK
COUNTY. DENSE FOG ADVISORY THROUGH 6 PM...THOUGH I EXPECT TO
EXTEND THIS AT 4 PM.

FULL SUN HEATING WELL UNDERWAY WITH TEMPS WELL INTO THE 80S
EXCEPT FOR THOSE REGIONS ALONG THE COAST (59 AT FIRE ISLAND IN THE
FOG AT LAST CHECK).

SIGNIFICANT INSTABILITY NOW OVER THE LOWER HUDSON VALLEY WITH
OVER 3000 J/KG OF SFC BASED CAPE WITH LI`S NEAR -8 C. EXPECT DEEP
CONVECTION TO FIRE OVER THE CATSKILLS BY 2 PM AND THEN SINK
SOUTHWARD. FIRST STORM ON LAKE BREEZE BETWEEN SYR AND ROC HAD
GOLF BALL SIZED HAIL WITH IT. WITH LIMITED SHEAR...SEVERE WIND
POTENTIAL IS LOW...BUT HAIL AND MORE POSSIBLY FLOODING COULD BE AN
ISSUE. FFG IS OVER 2 INCHES IN ONE HOUR...BUT SAW THE CAM`S
PRODUCING THESE AMOUNTS. WITH THE WEAK SHEAR AND PWAT`S NEAT 1.5
INCHES...HAVE HIGHLIGHTED THIS IN THE HAZARDOUS WEATHER OUTLOOK.
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&&

.SHORT TERM /6 PM THIS EVENING THROUGH 6 PM WEDNESDAY/...
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ANY LINGERING CONVECTION THIS EVENING DIMINISHES IN COVERAGE AS IS
SAGS SOUTH. MAIN ISSUE LATTER TONIGHT WILL BE THE DEVELOPMENT OF
FOG ONCE AGAIN AS SOUTHERLY WINDS PREVAIL AND THE AIRMASS REMAINS
QUITE MOIST.

LOWS WILL BE QUITE WARM...60S PER MOS.

FOR WEDNESDAY...RIDGE SLOWLY SHIFTS EAST AS UPSTREAM TROUGH
FINALLY MAKES EASTWARD PROGRESS. HOWEVER...ANOTHER WARM DAY IS ON
TAP. MORNING FOG AND STRATUS WILL GIVE WAY TO AT LEAST PARTIAL
SUNSHINE. CONVECTION SHOULD BE SCATTERED AT BEST WITH ONLY WEAK TO
MARGINAL INSTABILITY IN PLACE.
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&&

.LONG TERM /WEDNESDAY NIGHT THROUGH MONDAY/...
A COLD FRONT IS EXPECTED TO DROP SOUTHEAST FROM NEAR THE CANADIAN
BORDER WEDNESDAY NIGHT INTO THURSDAY MORNING. THE COLD FRONT IS
EXPECTED TO MOVE ACROSS THE AREA THURSDAY EVENING TRIGGERING SCT
SHOWERS AND THUNDERSTORMS. THIS FRONT WILL THEN MOVE OFFSHORE BY
FRIDAY MORNING WITH A WAVE OF LOW PRESSURE MOVING NORTHEAST ALONG
IT...KEEPING SHOWERS ACROSS THE AREA THROUGH FRIDAY AFTERNOON.

EXPECT HIGHS ON THURSDAY TO BE IN THE MID TO UPPER 70S WITH LOWS
THURSDAY NIGHT IN UPPER 50S TO AROUND 60.

FRIDAY NIGHT THROUGH MONDAY...AN AREA OF HIGH PRESSURE WILL
DROP SOUTHEAST FROM CENTRAL CANADA INTO THE CENTRAL US AND BUILD
EASTWARD THROUGH MEMORIAL DAY. HIGHS SATURDAY THROUGH MEMORIAL DAY
ARE EXPECTED TO BE IN THE UPPER 60S TO AROUND 70 WITH LOWS IN THE
MID 40S TO LOWER 50S.

&&

.AVIATION /18Z TUESDAY THROUGH SUNDAY/...
A FRONTAL BOUNDARY DRAPED FROM W TO E THROUGH NEW ENGLAND WILL
REMAIN NEARLY STATIONARY TODAY. IT MAY SINK SLIGHTLY S BUT IS
EXPECTED TO REMAIN N OF THE TERMINALS.

SLY FLOW TODAY WITH MAINLY VFR. VSBY REDUCTIONS POSSIBLE KJFK-
KISP...HOWEVER THE NRN EDGE OF THE IFR IS EXPECTED TO REMAIN JUST S
OF THE TERMINALS ATTM.

AIRMASS WILL BE VERY UNSTABLE THIS AFTN AND EVE...ESPECIALLY N
AND W OF THE CITY. ISOLD-SCT TSTMS WILL BE POSSIBLE...WITH
LOCATIONS FROM KBDR-KHPN-KSWF THE HIGHEST PROB OF BEING DIRECTLY
IMPACTED. ISOLD CELLS CANNOT BE RULED OUT ANYWHERE EXCEPT PERHAPS
LONG ISLAND.

SLY ONSHORE FLOW WILL CONTINUE TNGT. POTENTIAL FOR WIDESPREAD IFR
OR LOWER.

     NY METRO ENHANCED AVIATION WEATHER SUPPORT...

DETAILED INFORMATION...INCLUDING HOURLY TAF WIND COMPONENT FCSTS
CAN BE FOUND AT:  HTTP:/WWW.ERH.NOAA.GOV/ZNY/N90 (LOWER CASE)

KJFK FCSTER COMMENTS: LOW CHC OF EVENING CONVECTION. MVFR OR LOWER
POSSIBLE BEFORE 00Z WITH FOG RETURNING.

KLGA FCSTER COMMENTS: LOW CHC OF EVENING CONVECTION.

KEWR FCSTER COMMENTS: LOW CHC OF EVENING CONVECTION.

THE AFTERNOON KEWR HAZE POTENTIAL FORECAST IS YELLOW...WHICH
IMPLIES SLANT RANGE VISIBILITY 4-6SM OUTSIDE OF CLOUD.

KTEB FCSTER COMMENTS: MVFR HZ IS EXPECTED TO IMPROVE TO VFR AROUND
15-16Z. LOW CHC OF EVENING CONVECTION.

KHPN FCSTER COMMENTS: TSTMS POSSIBLE THIS AFTN AND EVE.

KISP FCSTER COMMENTS: PERIODS OF MVFR HZ POSSIBLE TODAY. IFR MAY
COME IN MUCH EARLIER THAN TAFS INDICATE THIS EVE.

.OUTLOOK FOR 12Z WEDNESDAY THROUGH SATURDAY...
.WED...IFR IN FOG AND STRATUS IMPROVING TO VFR IN THE MORNING. SCT
SHOWERS/TSTMS IN THE AFTN/EVE.
.WED NIGHT-FRI...SCT SHOWERS/TSTMS. AT NIGHT...IFR POSSIBLE WITH
STRATUS/FOG.
.SAT...VFR.

&&

.MARINE...
DENSE FOG ACROSS THE WATERS NEAR SHORE OCEAN AND GREAT SOUTH BAY.
THIS ADVECTION FOG IS EXPECTED TO PERSIST INTO WEDNESDAY.

SOUTH WINDS THIS AFTERNOON WITH SUB SCA CONDITIONS.

CONTINUED SOUTH TO SOUTHWEST FLOW IS FORECAST FOR TONIGHT AND
WEDNESDAY AS A FRONTAL BOUNDARY REMAINS TO THE NORTH. SEAS WILL
REMAIN BELOW 5 FT OVER THE OCEAN WATERS...1 FT OR LESS ELSEWHERE
TODAY AND LIKELY TONIGHT.

LATEST WAVE WATCH III GUIDANCE FOR THE OCEAN WATERS SUGGEST 5 TO
6 FT SEAS BY WEDNESDAY DUE TO PERSISTENT SOUTH FLOW AND POSSIBLE
SOUTHERLY SWELL. HOWEVER...WAVE WATCH HAS BEEN OVER FORECASTING
SEAS BY A FOOT OR TWO...SO CONFIDENCE IN THIS HAPPENING IS NOT
HIGH AT THIS TIME.

SEAS EXPECTED TO BE ABOVE SCA LEVELS WEDNESDAY NIGHT...WITH 25 KT
WIND GUSTS POSSIBLE ON THE OCEAN WATERS BY WEDNESDAY EVENING. A COLD
FRONT WILL MOVE ACROSS THE AREA WATERS THURSDAY EVENING INTO
THURSDAY NIGHT...WITH HIGH PRESSURE BUILDING IN AT THE SURFACE ON
LATE ON FRIDAY. WINDS COULD BE BELOW SCA LEVELS BY FRIDAY
MORNING...WITH SEAS REMAINING ABOVE SCA CRITERIA THROUGH SATURDAY
MORNING.

&&

.HYDROLOGY...
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SCT TSTMS THIS AFTERNOON...MAINLY LOWER HUDSON VALLEY. LOCALIZED
FLASH FLOODING WITH UP TO 3 INCHES POSSIBLE.

SCT SHOWERS/TSTMS WED-THU WILL BE CAPABLE OF PRODUCING LOCALLY HEAVY
RAINFALL...WITH THE BEST CHANCES NORTH/WEST OF NYC. TOTAL BASIN
AVG QPF FOR WED-THU COULD BE 1/4 TO 1/2 INCH...WITH LOCALLY HIGHER
AMTS IN TSTMS.

FOR DETAILS ON SPECIFIC AREA RIVERS AND LAKES...INCLUDING OBSERVED
AND FORECAST RIVER STAGES AND LAKE ELEVATIONS...PLEASE VISIT THE
ADVANCED HYDROLOGIC PREDICTION SERVICE /AHPS/ GRAPHS ON OUR WEBSITE.
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&&

.OKX WATCHES/WARNINGS/ADVISORIES...
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CT...NONE.
NY...DENSE FOG ADVISORY UNTIL 6 PM EDT THIS EVENING FOR NYZ080-081.
NJ...NONE.
MARINE...DENSE FOG ADVISORY UNTIL 10 AM EDT WEDNESDAY FOR ANZ345-350-
     353-355.
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&&

$$
SYNOPSIS...
NEAR TERM...
SHORT TERM...
LONG TERM...
AVIATION...JMC
MARINE...
HYDROLOGY...